In general, the term "embedded system" connotes a combination of computer hardware and software that forms a component of some larger system. Embedded systems are intended to operate without intervention by the larger system of which they form a part, and without the need for frequent control or supervisory inputs from any source. Embedded systems are usually of simple design, and often do not include mass storage components or complex peripherals.
Embedded systems have been placed in vending machines to provide a simple computer network interface to report the need for service or vended product replenishment. Some copying machines in the office environment also utilize embedded systems for reporting of operational status, and embedded systems have been suggested in television set-top boxes designed to provide Internet web browser features through the viewer's television set.
Embedded systems that are accessible over computer networks may be configured, for example, as specialized web servers designed for Internet access. In general, this web server function is restricted to embedded device interface. But the device must usually be able to supply data files used to specify and create interfaces.
In order to minimize space required for storing data files within the limited non-volatile memory of an embedded system, which would generally be limited to a few thousand bytes (8-bit memory locations) of EEPROM (electrically erasable, programmable read-only memory), a few fixed-length data files with a fixed address table could be provided. This type of data structure still requires storage space for the address table and a minimal file access utility (a READ routine, for example) to access the stored data.
While this stripped-down data structure may be adequate for some application, it lacks the flexibility to operate in an environment where data files may need to be altered, removed, or added. Accordingly, a need arises for a flexible file system designed to operate in conjunction with a microcomputer-based system having limited storage capability. Such a file system should provide a range of file system services while preserving as much as possible of the embedded system's storage capability for the data files themselves.